Planet Air

Analysis exploring air quality inequality across U.S. counties using EPA AQI data.

Project by: Kelly Chang, Jenny Zheng, Emily Chi

Questions

  1. Which counties or states experience the most Unhealthy or Hazardous Days?
  2. Compare exposure to specific pollutants (PM2.5, Ozone, NO₂) across counties.
  3. Visualize trends over time in AQI: identify improving or worsening regions.

States that Experience the Most Unhealthy or Hazardous Days

How does exposure to specific pollutants (PM2.5, Ozone, NO₂, PM10, CO) vary across counties?

This map visualizes the dominant air pollutant in each U.S. county based on the pollutant exposure days recorded in the EPA AQI dataset. Each county is color-coded by the pollutant with the greatest presencem, such as PM2.5, Ozone, or NO₂ allowing viewers to quickly identify regional pollution patterns.

Key findings: The spatial distribution of dominant pollutants reveals clear regional differences in air quality exposure across the United States. Ozone appears heavily concentrated in the Northeast and stretches across much of the Midwest and Southeast.

In contrast, PM2.5 is more widely dispersed across both western and eastern states, appearing frequently along the West Coast as well as across parts of the South and Midwest.

Other pollutants like PM10, NO₂, and CO appear less dominant overall and occur more sporadically, suggesting localized rather than regional trends.

How AOI Trend Change Across Different States in The Last 10 Years

Source Files